Armstrong joined AOL from Google (NASDAQ:GOOG) in 2009, where he oversaw Google's Americas advertising sales and operations teams.

"His deep experience with consumer-facing Internet businesses, Web marketing and search will be highly valued as the Priceline Group continues to expand its desktop and mobile travel service offerings around the globe,” Priceline.com CEO Jeffery Boyd said.

Priceline, based in Norwalk, Conn., is an online travel company that competes with the likes of Expedia (NASDAQ:EXPE), Tripadvisor (NASDASQ:TRIP) and Orbitz (NYSE:OWW).